Boys with normal stature with Tanner I sexual development will have 24 hour GH levels, LH and FSH pulsations for 24 hours. T and E2 levels determined every 4 months for 5-6 years as they progress through puberty. Their response to 3 doses of GHRH will be determined at each stage of sexual development. X-rays of L hand for BA will be obtained. Studies done to determine whether sexual development changes GH secretion; to establish longitudinal normative data on LH and FSH pulsations, and to correlate skeletal maturation with growth rate.